The present invention relates to a discharge container which receives a liquid such as a drug solution or the like, and discharges the liquid on the basis of a pump operation.
A pump portion 41 used for a conventional discharge container for discharging a liquid such as a drug solution or the like is provided, as shown in FIG. 10A, with a cylinder 42 filled with a drug solution 2, a piston provided within the cylinder 42 so as to freely oscillate and urged upward by a spring 43, and an outflow valve 45 formed by a flexible member, brought into contact with an outer peripheral portion of the piston 44 and oscillating within the cylinder 42 together with the piston 44. Further, the cylinder 42 is provided in a bottom portion with an inflow port 46 flowing the liquid into the cylinder 42 from a container (not shown) receiving the liquid, and a check ball 47 corresponding to an inflow valve passing the liquid flowed within the cylinder 42 and shutting the liquid supplied from the above. In the discharge container having the pump portion 41 in, accordance with the conventional art, when a user presses down the piston 44, the piston 44 and the outflow valve 45 are integrally pressed downward as shown in FIG. 10B, whereby a pressure is applied to the liquid within the cylinder 42. Since the check ball 47 provided in the bottom portion of the cylinder 42 shuts the liquid from the supplied from the above, the pressure is applied to the liquid within the cylinder 42. As mentioned above, when the pressure is applied to the liquid within the cylinder 42, the outflow valve 45 in an outer peripheral portion of the piston 44 is bent, whereby the liquid is flowed out upward from a gap between the outflow valve 45 and the piston 44.
Further, when the user takes off a hand from the piston 44, the piston 44 is pressed upward by the spring 43. At this time, the piston 44 and the outflow valve 45 are brought into contact with each other, whereby the outflow valve 45 is closed, so that the drug solution is sucked from the inflow port 46 via the check ball 47 so as to be charged within the cylinder 42.
In the conventional discharge container mentioned above, a state that the liquid is discharged is changed in correspondence to a speed at which the user presses the piston 44. For example, when the speed at which the piston 44 is pressed is high, the liquid is energetically discharged, however, when the speed at which the piston 44 is pressed is low, the liquid is discharged only little by little. Accordingly, for example, in the case that the discharge container is used as a spray for atomizing the drug solution in a vapor form, the drug solution is discharged in a vapor form if the speed at which the piston 44 is pressed is high, however, the drug solution is discharged in a liquid ball form not in a vapor form if the speed at which the piston 44 is pressed is low. In the case that the discharge container is used as the spray for applying the drug solution as mentioned above, since a diameter of an applied drop of the drug solution is changed in correspondence to a pressing way of the piston 44, there is a risk that a result of effect due to the drug application is changed.
Further, in the conventional discharge container mentioned above, since generally the discharge port for discharging the liquid and the piston 44 are integrally formed, the discharge port is pressed down when the piston 44 is pressed down. Accordingly, in the conventional discharge container, when discharging the liquid, the discharge port discharges the solution while moving down. Accordingly, even in the case that it is necessary for the user to discharge the liquid to an accurate position, the discharge port moves, so that it is hard to discharge to the accurate position.
An object of the present invention is to improve a discharge container, and further in order to solve the problem mentioned above, a detail object is to provide a discharge container which can discharge a liquid such as a drug solution or the like in a stable state.
In order to achieve the object mentioned above, in accordance with a first aspect of the present invention, there is provided a discharge container for discharging a liquid received within a container to an external portion on the basis of a pump operation, having the following features. At first, the discharge container is provided with a cylinder within which a liquid is charged, a first piston slidably provided within the cylinder and urged in a backward moving direction by a first spring, a second piston slidably provided within the cylinder and backward moving while compressing a second spring when the liquid within the cylinder is pressed by the first piston, an inflow port for flowing the liquid from the inner portion of the container to an inner portion of the cylinder, an inflow valve provided between the inflow port and the container, passing the liquid flowing into the cylinder and shutting an outflow of the liquid from the inner portion of the cylinder, an outflow port for flowing the liquid to the external portion from the inner portion of the cylinder, and a liquid passage connecting the outflow port to the discharge port.
Further, the cylinder has a small diameter portion having a small inner diameter, a large diameter portion having a large inner diameter and a step portion corresponding to a boundary therebetween, the first piston is provided within the small diameter portion, the second piston is provided within the large diameter portion so as to oppose to the first piston, the outflow port is formed near a front end portion of the first piston so as to direct to a sliding surface with the cylinder, the liquid passage is connected to the discharge port through the first piston, the inflow port is provided so as to pass through the second piston, the first piston is urged in a direction moving apart from the second piston by the first spring, the second piston is urged by the second spring so as to be brought into contact with the step portion.
Further, while the first piston moves at a predetermined stroke, the outflow port is closed, and the second piston moves backward while pressing and compressing the second spring by the liquid existing between the first piston and the second piston.
On the other hand, when the first piston moves over the predetermined stroke, the outflow port is opened, the second piston is pressed back to the second spring and the liquid within the cylinder is discharged to the external portion via the outflow port, the liquid passage and the discharge port due to an urging force of the second spring.
In the discharge container in accordance with the first aspect of the present invention, in the case that the first piston is pressed by the user, since the outflow port is closed until the predetermined stroke, the pressure is applied to the liquid received between the first piston and the second piston, the second spring is compressed and the second piston moves backward. Further, when the first piston is pressed over the predetermined stroke, the outflow port is opened, so that the liquid to which the pressure is applied from the second spring flows out from the outflow port, and the liquid is discharged to the external portion via the liquid passage and the discharge port.
As mentioned above, in the discharge container in accordance with the first aspect of the present invention, the liquid within the cylinder is urged by the second spring so as to be discharged. Therefore, in accordance with the discharge container of the present invention, since the pressure applied to the liquid at a time of discharging the liquid becomes uniform, it is possible to always discharge in a stable state. Accordingly, even in the case that the discharge container in accordance with the present invention is used in the spray for spraying the drug solution, since the state of the sprayed drug solution is stable, a diameter of an applied drop of the drug solution is not changed, and a result of effect due to the drug application becomes uniform. Further, in the case that the user presses the first piston, the liquid is not discharged until the predetermined stroke and the liquid is discharged when being over the predetermined stroke. Accordingly, when the outflow port is connected to the first piston, a moving amount of the discharge port at a time when the liquid is discharged from the discharge port becomes a little, so that the user can discharge the liquid to an accurate position.
Further, as shown in FIG. 3, the structure may be made such that the cylinder is constituted by an outer cylinder formed in a cylindrical body having a bottom, and an inner cylinder provided within the outer cylinder and having a bottom portion communicated with the outer cylinder via a communication portion, the first piston is formed in a cylindrical shape and outward fitted to the inner cylinder, a lower end portion of the first piston is slidably in contact with an inner peripheral surface of the outer cylinder and an outer peripheral surface of the inner cylinder, the second piston is provided within the inner cylinder, the liquid passage is formed in a gap between an inner peripheral surface above the lower end portion of the first piston and the outer peripheral surface of the inner cylinder, the outflow port is formed between the inner peripheral surface of the first piston and the communication portion in a state that the lower end portion of the first piston passes through the communication portion, the inflow port is provided in the bottom portion of the inner cylinder, the first piston is urged in a direction moving apart from the bottom portion of the outer cylinder by the first spring, the second piston is urged toward the bottom portion of the inner cylinder by the second spring, and when the first piston moves over the predetermined stroke, the lower end portion of the first piston moves over the communication portion and the outflow port is opened.
Further, as shown in FIG. 5, the structure may be made such that the cylinder is constituted by an outer cylinder formed in a cylindrical body having a bottom, and an inner cylinder formed on an inner peripheral surface of a cylindrical second piston provided within the outer cylinder, the second piston is slidably in contact with an inner peripheral surface of the outer cylinder and having a bottom surface portion facing to the liquid within the cylinder, the first piston is provided within the inner cylinder, a lower end portion of the first piston is slidably in contact with an inner peripheral surface of the inner cylinder toward a bottom surface of the outer cylinder, the liquid passage is formed above the lower end portion with a gap with respect to the inner peripheral surface of the inner cylinder, the outflow port is formed between the bottom surface portion of the second piston and the lower end portion of the first piston in a state that the lower end portion of the first piston protrudes out from the bottom surface portion of the second piston, the inflow port is provided in the bottom surface of the outer cylinder, the first piston is urged in a direction moving apart from the bottom portion of the outer cylinder by the first spring, the second piston is urged toward the bottom portion of the outer cylinder, and when the first piston moves over the predetermined stroke, the lower end portion of the first piston moves over the bottom surface portion of the second piston and the outflow port is opened.
Further, as shown in FIG. 7, the structure may be made such that the cylinder is formed in a cylindrical shape, the first piston and the second piston are provided within the cylinder so as to oppose to each other, the outflow port is open to a side surface of the cylinder corresponding to a part of a stroke of the second piston, the inflow port is provided so as to extend through the second piston, the first piston is urged in a direction moving apart from the second piston by the first spring, the second piston is urged toward the first piston by the second spring, while the first piston moves to the predetermined stroke, the outflow port is closed by a side surface of the second piston, and when the first piston moves over the predetermined stroke, the second piston is pressed, an end portion in a side of the first piston moves over the outflow port and the outflow port is opened.
Further, a discharge container in accordance with a second aspect of the present invention is provided with the following features. At first, there is provided a discharge container for discharging a liquid received within a container to an external portion from a discharge port on the basis of a pump operation, provided with a case with a bottom held in the container, a first piston provided on a bottom surface of the case, a cylinder outward fitted to the first piston within the case and filled with a liquid therewithin, a second piston provided within the cylinder with a predetermined gap with respect to the first piston, a first spring urging the cylinder upward, a second spring urging the second piston to a side of the first piston, an inflow port extending through the first piston so as to flow the liquid from the container into the cylinder, an inflow valve provided between the inflow port and the container so as to pass the liquid flowing into the cylinder and prevent the liquid from flowing out from the inner portion of the cylinder, an outflow valve urged to an upper surface of the second piston by the second spring so as to be brought into contact therewith, having an outer peripheral portion protruding from an outer peripheral edge of the second piston so as to be slidably brought into contact with an inner peripheral surface of the cylinder and having a portion protruding out from the outer peripheral edge of the second piston and facing to the liquid within the cylinder, an outflow port formed in a contact portion between the outflow valve and the second piston and flowing out the liquid to an external portion from an inner portion of the cylinder, a liquid passage connecting the outflow port to the discharge port, and a gap holding member arranged between an upper surface of the first piston and a lower surface of the second piston so as to keep a gap between the both.
Further, a recess portion to which the gap holding member can be inserted in a moving direction at a predetermined distance is provided on a surface of the second piston opposing to the first piston, and a guide portion for guiding the gap holding member to the recess portion when the cylinder is pressed down is provided in the cylinder.
The gap holding member is held by the first spring in a state of being out of the recess portion when the cylinder is not pressed down. When pressing downward the cylinder to the predetermined stroke, the gap holding member is brought into contact with the first piston and the second piston in a state of being out of the recess portion so as to press and compress the second spring while keeping a gap between the both. When pressing down the cylinder over the predetermined stroke, the gap holding member is guided by the guiding member so as to be inserted to the recess portion, and the gap holding member press down the second piston downward at a distance that the gap holding member is inserted to the recess portion by the second spring, thereby applying a pressure to the liquid within the cylinder. Then, the second spring is pressed and compressed by the pressure of the liquid, the outflow valve is opened so as to open the outflow port, and the liquid is flowed out to the external portion via the outflow port, the liquid passage and the discharge port.
In the discharge container in accordance with the second aspect of the present invention, the first piston is provided within the cylinder, and the second piston is provided therewithin at a position opposing to the first piston. Further, the gap holding member is arranged between the first piston and the second piston. Accordingly, in the case that the cylinder is pressed by the user, the first piston relatively moves within the cylinder until the predetermined stroke by the gap holding member while moving the second piston backward. Accordingly, the second spring is compressed by the second piston, however, since the gap between the first piston and the second piston is held by the gap holding member and is not changed, no pressure is applied to the liquid existing between the both.
Further, when the cylinder is pressed over the predetermined stroke, the gap holding member is inserted to the recess portion provided in the first piston or the second piston. Accordingly, the gap holding member keeping the gap between the first piston and the second piston is taken out from the portion between the both, and the second piston is pressed to the side of the first piston by the compressed second spring. Therefore, the pressure is applied to the liquid between the first piston and the second piston, and the outflow valve is opened, whereby the liquid within the cylinder is discharged to the external portion from the outflow port via the liquid passage and the discharge port.
As mentioned above, in the discharge container in accordance with the second aspect of the present invention, in the same manner as that of the first aspect, since the liquid within the cylinder is urged by the second spring so as to be discharged, the pressure applied to the liquid at a time of discharging the liquid becomes uniform, so that the liquid is always discharged in a stable state. Further, in the same manner as that of the first aspect, since the liquid is not discharged until the predetermined stroke and the liquid is discharged when being over the predetermined stroke, the user can discharge the liquid at an accurate position.